Something remarkable has been happening to me in the past 19 days. Wherever I go, no one launches abuse at me. When I open my mouth to speak, I am received with civility and the occasional "Have a good one". I am not attacked or intimidated. Where have I been visiting for the past two and a half weeks? Philadelphia. And where do I live? London.

Here is a scenario from my adopted hometown: a month ago, I was travelling on a double-decker bus. A well-dressed woman boarded with her son, respectable in his school uniform. Ahead of her was an elderly American woman, who said, "I beg your pardon, I didn't mean to bang into you." This prompted a tirade from the Englishwoman - let's call her Lady E. "I rejoice every time I hear of another American soldier dying! You people are destroying the world".

The American - let's call her Mrs A - fought back: "I personally am not destroying the world." This only provoked Lady E more, and she screamed into the American's face: "I wish every one of you would leave this country and not set foot in it ever again." Mrs A began crying. "Thank you for ruining my trip." Lady E lunged at the American and began to shake her. I jumped up and shouted for the driver to stop and for her to leave the woman alone, prompting Lady E to come over and grab me. "Another bloody American! You are scum." Thankfully, the woman next to me pushed her away. I left the bus. Mrs A sat sobbing.

Did I imagine this? No. Was the Englishwoman a crazy? No.

I don't like what is happening in Britain, and am dismayed at the level at which anti-Americanism has peaked in recent months. Does anyone say "George Bush" or "Donald Rumsfeld" or "Dick Cheney" when they fly into these tirades? No. In fact, the visceral, in-your-face America-hatred goes back long before the days of the Bush regime.

When Bill Clinton was president, I attended a human-rights conference at my local synagogue in St John's Wood. During the tea break, I asked a man at one of the booths for a leaflet. He heard my accent and launched into a red-faced screeching session about the evils of American empire and of the "nazism" and "fascism" promulgated by the US. A black man came over and began shouting about America having "invented slavery" and a delicate elderly lady joined the fray to bellow about the Zionists running America and the "genocides" perpetrated by Americans since the days of William Penn. I wondered why I had ventured out on a Sunday to be with like-minded people concerned about human rights, only to be reduced to a gibbering jelly as an ugly, strident crowd grew around me.

I have lived in Europe for all of my adult life, and from the day I arrived I have been aware not only of an oft-blatant anti-semitism but also a resentment of Americans among colleagues, teachers, my social circle and neighbours. What is significant about this rage is that it emanates not from the great unwashed but from the educated and intellectual classes.

We all know about the academic boycotts of Israeli scholars. We all know about poor Philip Lader, the former US ambassador, who was reduced to tears on Question Time as David Dimbleby dispassionately watched a studio audience stomping its feet and shouting anti- American epithets two days after 9/11. I cannot conduct business or even take a taxi ride in Britain without a scathing tirade about the scurrilous Yanks. The day after 9/11, a minicab driver informed me that the "yellow Americans" on the four hijacked planes were typical of the way "the Yanks do battle - they chicken out and let the Brits do the dirty work".

As far as the Guardian-reading classes are concerned, my hunch is that the relentless America-bashing in the European media, combined with the abundance of criticism of Israel, has created an atmosphere of hostility that makes me fearful for my safety in my beloved adopted country.

We have Islamic extremists in Britain holding "festivals" to celebrate the "magnificent 19 of September 11". And last November, when George Bush visited the UK and London's mayor, Ken Livingstone, boycotted the state banquet, ordinary folk gathered in Trafalgar Square to burn and stomp on the Stars and Stripes.

I hesitate to blame the media. But I have stopped going to meetings of my trade union, the National Union of Journalists, because I cannot listen to incessant vitriol about the crimes of my native country. Yes, there is much to worry about in present US policy, but how many American trade unions spend hours devising resolutions to censure their most trusted and valued ally? How many Americans invite expat Brits to their dinner table only to abuse and intimidate them? Friends tell me that the US is one giant fundamentalist-Christian nation of Bible-bashers. Otherwise enlightened colleagues tell me that the US "threatens the world far more than Bin Laden".

Where will it all end? I know many expat Americans - including non-Jews - who have received dressing-downs at social and professional gatherings. The standard reprimand contains the list of American misdemeanors: the Project for the New American Century taking over the world's governments; Wolfowitz, Perle and other "Zionists" bullying the Bush and Blair governments into war with Iraq; and American Jews running the world's media, banks and industries.

Here is what I perceive as the explanation: Europe has always been a seething hotbed of anti-semitism. England, sadly, has the distinction of being the very first country to expel its Jews and initiate the blood libel. The Jews were not allowed back into England until the time of Cromwell, and feel to this day that they worship by the grace of the sovereign. It is impossible to convey to Americans inside the US, or to American Jews, the open loathing of both groups that dominates daily life outside the US today.

I am aware that many Americans are leaving their homes abroad and returning home after decades in Europe because they can no longer endure the daily abuse. Anti-Americanism is not a result of Abu Ghraib or of a Rumsfeldian pronouncement. It is a disturbing and hurtful form of psychosis that is rapidly eroding the all-important special relationship.

I do not yet fear for my life in St John's Wood, but it sure is heaven strolling around the artists' studios at the Torpedo factory in Alexandria, Virginia and being greeted as me, not as a bloody American or an accursed Jew.

· Carol Gould is a playwright and journalist. This is an extract from a longer article which appeared first on frontpagemag.com